COMPUTER HARDWARE SERVICING; TESDA COMPETENCIESThis is an online lecture in Computer Hardware Servicing, prepared by Mr. George P. Lumayag, ICT Coordinator. These Skills Learning Competencies are patterned from TESDA in preparation of the K to 12 implementation.
Electro-Static Discharge (ESD) ToolsStatic electricity is easily generated by friction on carpets, tile flooring, clothing, hair, fabric, and etc. The friction of moving air alone will charge suspended parties and cause the buildup of static electrical charges on people and objects in the environment. Grounded antistatic work mats used electrostatic electricity. Examples of ESD Tools:
Anti-static wrist strap
Anti-static wrist strap-used to prevent ESD damage to computer equipment.
Anti-static mat
Anti-static - used to stand on or place hardware on to prevent static electricity from building up.
Hand ToolsA hand tool is a device for performing work on a material or a physical system using only hands. The hands tools can be manually used employing force, or electrically powered, using electrical current. Examples of Hand Tools:
Flat head screwdriver
Flat head screwdriver - used to loosen or tighten slotted screws.
Philips head screwdriver
Philips head screwdriver - used to loosen or tighten cross-head screws.
Torx screwdriver
Torx screwdriver - used to loosen or tighten screws that have a star-like depression on the top, a feature that is mainly found laptop.
Hex driver
Hex driver - sometimes called a nut driver, is used to tighten nuts in the same way that a screwdriver tightens screws.
Needle-nose plier
Needle-nose plier - used to hold small parts.
Wire cutter
Wire cutter - used to strip and cut wires.
Tweezers
Tweezers - used to manipulate small parts.
Part retriever
Part retriever - used to retrieve parts from location that are too small for your hand to fit.
Flashlight
Flashlight - used to light up areas that you cannot see well.
Cleaning ToolsHaving the appropriate cleaning tools is essential when maintaining or repairing computers. Using these tools ensures the computer components are not damage during cleaning. Examples.
Lint-free cloth
Lint-free cloth - used to clean different computer components without scratching or leaving debris.
Compressed air
Compressed air - used to blow away dust and debris from different computer parts without touching the components.
Cable ties
Cable ties - used to bundle cables neatly inside and outside of a computer.
Parts organizer
Parts organized - used to hold screw, jumpers, fasteners and other small parts and prevents them from getting mixed together.
Diagnostic ToolsComputers are easier to use and more dependable with each new generation of hardware and operating system update, but that doesn't mean they're problem-free. Here's the most popularb tools for diagnosing your computer problems:
Multimeter
Multimeter -used to test the integrity of circuits and the quality of electricity in computer components.
Loopback Adapter
Loopback Adapter - used to test the functionality of computer ports.
PC Tools for Software and Hardware Trouble Shooting.These are the PC Tools and Components that will be used in PC Hardware and Software Trouble Shootings.
A lens
A lens is an optical device which transmits and refracts light, converging or diverging the beam.[citation needed] A simple lensconsists of a single optical element. A compound lens is an array of simple lenses (elements) with a common axis; the use of multiple elements allows more optical aberrations to be corrected than is possible with a single element. Lenses are typically made of glass or transparent plastic. Elements which refract electromagnetic radiation outside the visual spectrum are also called lenses: for instance, a microwave lens can be made from paraffin wax.http://en.wikipedia.org/wiki/Lens_(optics)
A ruler
A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing and engineering/building to measure distances and/or to rule straight lines. Strictly speaking, the ruler is essentially a straightedge used to rule lines[citation needed], but typically the ruler also contains calibrated lines to measure distances.[1] http://en.wikipedia.org/wiki/Ruler
A T-square
A T-square is a technical drawing instrument used by draftsmen primarily as a guide for drawing horizontal lines on a drafting table. It may also guide a set square to draw vertical or diagonal lines. Its name comes from the general shape of the instrument where the horizontal member of the T slides on the side of the drafting table. T-squares come in varying sizes, common lengths being 18", 24", 30", 36" and 42".[citation needed]
T-squares are also used to measure and cut drywall. Drywall T-squares are typically made of aluminium and have a 48-inch (1,220 mm) long tongue.
Higher-end table saws are often equipped with T-square fences. These table saw fences are attached to a rail only on the front side of the table unlike traditional fences which clamp to both the front and the rear of the table.http://en.wikipedia.org/wiki/T-square
Steel rules
Steel rules come in rigid and flexible versions. While their primary purpose is accurate measurement, they can also be used as guides for laying out lines, and if rigid enough, for cutting. The thinner, more flexible rules can also be used to measure rounded or cambered work.
The differences in the prices of rules result from the various production methods, which also determine accuracy and legibility. Most rules are made by cutting the required length from a roll of band spring steel, with etched graduations. Rules made by this method are adequate for most applications and reasonably priced.
Higher-priced rules are cut, not stamped, from plate steel (stamping would cause the material to warp), and the edges are ground. Graduations are machined, much deeper than etched graduations, longer-lasting, and easier to read in poor light. http://www.fine-tools.com/mass.htm
A protractor
In geometry, a protractor is a square, circular or semicircular tool, typically in transparent perspex, for measuring angles. The units of measurement utilized are usually degrees (°).
They are used for a variety of mechanical and engineering-related applications, but perhaps the most common use is in geometry lessons in schools.
Some protractors are simple half-discs. More advanced protractors, such as the bevel protractor, have one or two swinging arms, which can be used to help measure the angle.
http://en.wikipedia.org/wiki/Protractor
An electronic calculator
An electronic calculator is a small, portable, usually inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.
The first solid state electronic calculator was created in the 1960s, building on the history of tools such as the abacus, developed around 2000 BC; and the mechanical calculator, developed in the 17th century. It was developed in parallel with the analog computers of the day.
Pocket-sized devices became available in the 1970s, especially after the invention of the microprocessor developed serendipitously byIntel for a Busicom calculator.
Modern electronic calculators vary from cheap, give-away, credit-card sized models to sturdy desktop models with built-in printers. They became popular in the mid-1970s as integrated circuits made their size and cost small. By the end of that decade, calculator prices had reduced to a point where a basic calculator was affordable to most and they became common in schools. http://en.wikipedia.org/wiki/Calculator
A multimeter
A multimeter or a multitester, also known as a VOM (Volt-Ohm meter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current andresistance. Multimeters may use analog or digital circuits--analog multimeters (AMM) and digital multimeters (often abbreviatedDMM or DVOM.) Analog instruments are usually based on a microammeter whose pointer moves over a scale calibrated for all the different measurements that can be made; digital instruments usually display digits, but may display a bar of a length proportional to the quantity being measured.
A multimeter can be a hand-held device useful for basic fault finding and field service work or a bench instrument which can measure to a very high degree of accuracy. They can be used to troubleshoot electrical problems in a wide array of industrial and household devices such as electronic equipment, motor controls, domestic appliances, power supplies, and wiring systems. http://en.wikipedia.org/wiki/Multimeter
An eraser
An eraser (US) or rubber (elsewhere) is an article of stationery that is used for removing pencil markings. Erasers have a rubbery consistency and are often pink or white. Some pencils have an eraser on one end. Typical erasers are made fromsynthetic rubber, but more expensive or specialized erasers are vinyl, plastic, or gum-like materials. Cheaper erasers can be made out of synthetic soy-based gum.
An eraser can be used of cleaning the RAM, a memory chip of the PC.
http://www.nlm.nih.gov/medlineplus/ency/article/002816.htm
paint brush
brush 1 (brsh)
n.
1. a. A device consisting of bristles fastened into a handle, used in scrubbing, polishing, or painting.
b. The act of using this device.
2. A light touch in passing; a graze.
3. An instance of contact with something undesirable or dangerous: a brush with the law; a brush with death.
4. A bushy tail: the brush of a fox.
5. A sliding connection completing a circuit between a fixed and a moving conductor.
6. A snub; a brushoff.
http://www.thefreedictionary.com/Paint+brush
A vacuum
A vacuum is a space devoid of air or matter, or a tool that uses suction to clean.(noun)
1. An example of a vacuum is a space with nothing in it.
2. An example of a vacuum is something used to clean up dirt on a floor.
To vacuum is to clean using a tool that sucks dirt or other elements into a storage container. (verb)
An example of vacuum is to clean the dirt off the carpet using a vacuum cleaner.
http://www.yourdictionary.com/vacuum
A soldering gun
A soldering gun is an approximately pistol-shaped tool for soldering metals using tin-based solder to achieve a strong mechanical bond with good electrical contact. The tool has a trigger-style switch so it can be easily operated with one hand. The body of the tool contains a transformer with a primary winding connected to mains electricity when the trigger is pressed, and an incomplete single-turn secondary winding of thick copper with very low resistance. A soldering tip, made of a loop of thinner copper wire, is secured to the end of the transformer secondary by screws, completing the secondary winding. When the primary of the transformer is energized, several hundred amperes of current flow through the secondary and very rapidly heat the copper tip. Since the tip has a much higher resistance than the rest of the tubular copper winding, the tip, used for soldering, gets very hot while the remainder of the secondary warms much less. A tap on the primary winding is often used to light a pilot lamp which also provides illumination of the workpiece. http://en.wikipedia.org/wiki/Soldering_gun
Pliers
Pliers are a hand tool used to hold objects firmly, for bending, or physical compression. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longerhandles on the other side. This arrangement creates a mechanical advantage, allowing the force of the hand's grip to be amplified and focused on an object with precision. The jaws can also be used to manipulate objects too small or unwieldy to be manipulated with the fingers. http://en.wikipedia.org/wiki/Pliers
Diagonal pliers
Diagonal pliers (or wire cutters or diagonal cutting pliers) are pliers intended for the cutting of wire (they are generally not used to grab or turn anything). The plane defined by the cutting edges of the jaws intersects the joint rivet at an angle or "on a diagonal", hence the name. Instead of using a shearing action as with scissors, they cut by indenting and wedging the wire apart. The jaw edges are ground to a symmetrical "V" shape; thus the two jaws can be visualized to form the letter "X", as seen end-on when fully occluded. The pliers are made of tempered steel with inductive heating and quenching often used to selectively harden the jaws.
http://en.wikipedia.org/wiki/Diagonal_pliers
A Phillips screw driver
A Phillips screw driver is primarily used to fasten and unfasten screws with a star-like hole in their heads.
Read more: http://wiki.answers.com/Q/What_is_the_use_of_a_Philips_screwdriver#ixzz1yYGur1jE
http://wiki.answers.com/Q/What_is_the_use_of_a_Philips_screwdriver
A screwdriver
A screwdriver is a tool for driving screws or bolts with special slots, and sometimes for rotating other machine elements with the mating drive system. The screwdriver is made up of a head or tip, which engages with a screw, a mechanism to apply torque byrotating the tip, and some way to position and support the screwdriver. A typical hand screwdriver comprises an approximately cylindrical handle of a size and shape to be held by a human hand, and an axial shaft fixed to the handle, the tip of which is shaped to fit a particular type of screw. The handle and shaft allow the screwdriver to be positioned and supported and, when rotated, to apply torque. Screwdrivers are made in a variety of shapes, and the tip can be rotated manually or by an electric motor or other motor. http://en.wikipedia.org/wiki/Screwdriver
The flat head is also one of the most abused tools, often substituted for any number of other tools that might not be available. The fact is the flat head screwdriver is quite useful for more than tightening screws. Used for light prying, scraping, nudging or holding it can be pretty versatile. Treat it too badly, though, and it'll snap, leaving you with a fishing weight in your toolbox. http://autorepair.about.com/od/tools/a/tools_flathed.htm
Goggles or safety glasses
Goggles or safety glasses are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and in woodworking. They are often used in snow sports as well, and in swimming. Goggles are often worn when using power tools such as drills or chainsaws to prevent flying particles from damaging the eyes. Many types of goggles are available as prescription goggles for those with vision problems. http://en.wikipedia.org/wiki/Goggles
A glove
A glove (Middle English from Old English glof) is a garment covering the whole hand. Gloves have separate sheaths or openings for eachfinger and the thumb; if there is an opening but no covering sheath for each finger they are called "fingerless gloves". Fingerless gloves with one large opening rather than individual openings for each finger are sometimes called gauntlets. Gloves which cover the entire hand or fist but do not have separate finger openings or sheaths are called mittens. Mittens are warmer than gloves made of the same material because fingers maintain their warmth better when they are in contact with each other. Reduced surface area reduces heat loss. http://en.wikipedia.org/wiki/Glove
LAN tester
· What are the features of LAN tester?
· How do you establish LAN to LAN connection?
The traffic has to go through a router to connect one network to another. Read More
· What does a LAN does?
A "LAN" stands for Local Area Network. It's just what it sounds like. A group of private computers that are connected by a common private network. If you have 2 computers in your home, and they are... Read More
· What is a LAN?
a LAN is a Local Area Network Answer. A LAN is the short abbreviation for Local Area Network. In a LAN you usually have many computers connected together using ehternet, Wifi, etc. The computers in... Read More
· What are LANs?
LAN stands for Local Area Network. A computing term for a method of connecting computers, generally using wires, and generally in the one building. Read More
http://wiki.answers.com/Q/What_is_LAN_tester
An antistatic wrist strap
An antistatic wrist strap, ESD wrist strap, or ground bracelet is an antistatic device used to safely ground a person working on very sensitive electronic equipment, to prevent the buildup of static electricity on their body, which can result in electrostatic discharge (ESD). It is used in the electronics industry by workers working on electronic devices which can be damaged by ESD, and also sometimes by people working around explosives, to prevent electric sparks which could set off an explosion. It consists of a stretchy band offabric with fine conductive fibers woven into it, attached to a wire with a clip on the end to connect it to a ground conductor. The fibers are usually made of carbon or carbon-filled rubber, and the strap is bound with a stainless steel clasp or plate. They are usually used in conjunction with an antistatic mat on the workbench, or a special static-dissipating plastic laminate on the workbench surface.http://en.wikipedia.org/wiki/Antistatic_wrist_strap
A crimping tool
A crimping tool is a tool designed to crimp or connect a connector to the end of a cable. For example, network cables and phone cables are created using a crimping tool to connect the RJ-45 and RJ-11 connectors to the end of the cable. In the picture to the right, is an example of what a crimping tool looks like. This example shows a tool capable of crimping both RJ-11 and RJ-45 connectors.http://www.computerhope.com/jargon/c/crimp.htm
Sharp Pointed Tweezers
The Tweezerman Pointed Tweezers feature perfectly aligned, hand filed tips made from 100 stainless steel. The fine, precision design makes eliminating even the most stubborn stray hairs a cinch.Caution: Tweezers are very sharp. Use with care. Keep out of the reach of children.Tweeze in the direction of hair growth, after a hot shower, or use a hot wash cloth to open pores. For ingrown hairs, cleanse skin and disinfect the tips of the tweezers with alcohol. After any work under the skin, clean area with hydrogen peroxide. Always replace protective cap on tweezer tips. http://reviews.sephora.com/8723/P63915/reviews.htm
A soldering iron
A soldering iron is a hand tool used in soldering. It supplies heat to melt the solder so that it can flow into the joint between two workpieces.
A soldering iron is composed of a heated metal tip and an insulated handle. Heating is often achieved electrically, by passing an electric current (supplied through an electrical cord or battery cables) through a resistive heating element. Portable irons can be heated by combustion of gas stored in a small tank, often using a catalytic heater rather than a flame. Simple irons less commonly used than in the past were simply a large copper bit on a handle, heated in a flame.
Soldering irons are most often used for installation, repairs, and limited production work in electronics assembly. High-volume production lines use other soldering methods.[1] Large irons may be used for soldering joints in sheet metal objects. Less common uses includepyrography (burning designs into wood) and plastic welding.http://en.wikipedia.org/wiki/Soldering_iron
An operating system
An operating system is a program designed to run other programs on a computer. A computer’s operating system is its most important program. It is considered the backbone of a computer, managing both software and hardware resources. Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays. They also manage files on computer hard drives and control peripherals, like printers and scanners.http://www.wisegeek.com/what-is-an-operating-system.htm
An application program
An application program (sometimes shortened to application) is any program designed to perform a specific function directly for the user or, in some cases, for another application program. Examples of application programs include word processors; database programs; Web browsers; development tools; drawing, paint, and image editing programs; and communication programs. Application programs use the services of the computer's operating system and other supporting programs. The formal requests for services and means of communicating with other programs that a programmer uses in writing an application program is called the application program interface (API).http://searchsoftwarequality.techtarget.com/definition/application-program
An oscilloscope
An oscilloscope, previously called an oscillograph, and informally known as a scope, CRO (for cathode-ray oscilloscope), or DSO (for the more modern digital storage oscilloscope), is a type of electronic test instrument that allows observation of constantly varying signalvoltages, usually as a two-dimensional graph of one or more electrical potential differences using the vertical or 'Y' axis, plotted as a function of time (horizontal or 'x' axis). Many signals, for example sound, can be converted to voltages and displayed this way. Signals are often periodic and repeat constantly, so that multiple samples of a signal which is actually varying with time are displayed as a steady picture. Many oscilloscopes (storage oscilloscopes) can also capture non-repeating waveforms for a specified time, and show a steady display of the captured segment.
Oscilloscopes are commonly used to observe the exact wave shape of an electrical signal. Oscilloscopes are usually calibrated so that voltage and time can be read as well as is possible by eye. This allows the measurement of, for example, peak-to-peak voltage of a waveform, the frequency of periodic signals, the time between pulses, the time taken for a to rise to full amplitude (rise time), and relative timing of several related signals.[1]
Oscilloscopes are used in the sciences, medicine, engineering, and telecommunications industry. General-purpose instruments are used for maintenance of electronic equipment and laboratory work. Special-purpose oscilloscopes may be used for such purposes as analyzing an automotive ignition system, or to display the waveform of the heartbeat as an electrocardiogram. Some computer sound software allows the sound being listened to to be displayed on the screen as by an oscilloscope.
Before the advent of digital electronics oscilloscopes used cathode ray tubes as their display element (hence were commonly referred to as CROs) and linear amplifiers for signal processing. More advanced storage oscilloscopes used special storage CRTs to maintain a steady display of a single brief signal. CROs were later largely superseded by digital storage oscilloscopes (DSOs) with thin panel displays, fast analog-to-digital converters and digital signal processors. DSOs without integrated displays (sometimes known as digitisers) are available at lower cost, and use a general-purpose digital computer to process and display waveforms. http://en.wikipedia.org/wiki/Oscilloscope
A hub
A hub is a piece of hardware that contains several ethernet ports that connects several computers. Connecting a hub to a network is very easy. You can simply connect a hub to your router, and then several computers to the hub. The IP addresses of the computers that are connected to the hub are assigned by the router it is connected to.
Hubs work by broadcasting data to all computers that are connected to it. When a computer or program makes a request for information from another computer, the originating computer sends (broadcasts) the request to the hub. The hub will then brodcast the request to all computers that are connect to it. When the destination computer receives the request, it sends the information back to the hub. Once again the hub broadcasts the information to all computers, with only the requesting computer acting on the information.
The downside to this type of connection is that the bandwidth is subdivided between the number of computers that are connected to the hub. If you have a 100Mbps connection, and 2 computers connected to the hub, then the bandwidth available to each computer is 50Mbps. With 4 computers, the bandwidth drops to 25Mbps.
An alternative to hubs are switches.
RJ45
RJ45 may refer to:
§ RJ45 (telecommunications), a connector standard for telephone cables
§ RJ45 (computers), a connector for computer network (Ethernet) cables
§ Modular connectors come in four sizes: 4-, 6-, 8-, and 10-position, where a position is a location for a contact. Not all of the positions may have contacts installed. When contacts are omitted, they are typically done so from the outermost pair of contacts inward, such that the number of contacts is almost always an even number. The insulating plastic bodies of 4P and 6P connectors have different widths, whereas 8P or 10P connectors share an even larger body width. The connector body positions with omitted contacts or contacts unattached to wires are unused for the electrical connection, but ensure that the plug fits correctly. For instance, RJ11 cables often have connectors with 6 positions and 4 contacts, to which are attached just 2 wires.
§ The connectors are designated with two numbers that represent the quantity of positions and contacts, with each number followed by a "P" and "C", respectively: for example, "6P2C" for a connector having 6 positions and 2 contacts. Alternate designations omit the "P" and "C" while separating the position and contact quantities with either an "x" ("6x2") or a slash ("6/2").
§ Internally, the contacts have sharp prongs that when crimped, pierce the insulation and connect with the wire conductor, a mechanism known as insulation displacement. Ethernet cables, in particular, may have solid or stranded wire conductors and the sharp prongs are different in the 8P8C connectors made for each type of wire. A modular plug for solid (single strand) wire often has three slightly splayed prongs on each contact to securely surround and grip the conductor. Modular plugs for stranded or tinsel wire have prongs that are designed to connect to multiple wire strands. Connector plugs are designed for either solid or stranded wire; a plug for one wire type might not make reliable contact when crimped to a cable with wires of the other type.
§ The dimensions of the connectors are such that a plug can be inserted into a jack that has more positions than the plug, leaving the jack's outermost contacts unconnected. However, not all plugs from all manufacturers have this capability, and some jack manufacturers warn that their jacks are not designed to accept smaller plugs without damage. If an inserted plug lacks contact slots at the outermost extremes, it may permanently deform the outmost contacts of an incompatible jack.
§ The contact positions are numbered sequentially starting from 1. When viewed head-on with the retention mechanism on the bottom, jacks will have contact position number 1 on the left and plugs will have it on the right. Contacts are numbered by the contact position. For example, on a 6-position, 2-contact plug, where the outermost four positions do not have contacts, the innermost two contacts are numbered 3 and 4.
§ Some modular connectors are indexed: their dimensions are intentionally non-standard, preventing connections with connectors of standard dimensions. The means of indexing may be non-standard cross-section dimensions or shapes, retention mechanism dimensions, or retention mechanism quantity. For example, a Modified Modular Jack (MMJ) using an offset latching tab was developed by Digital Equipment Corporation (DEC) to prevent accidental interchange of data and telephone cables.
http://en.wikipedia.org/wiki/RJ45
RJ45
RJ45 is a standard type of connector for network cables. RJ45 connectors are most commonly seen with Ethernet cables and networks.
RJ45 connectors feature eight pins to which the wire strands of a cable interface electrically. Standard RJ-45 pinouts define the arrangement of the individual wires needed when attaching connectors to a cable.
Several other kinds of connectors closely resemble RJ45 and can be easily confused for each other. The RJ-11 connectors used with telephone cables, for example, are only slightly smaller (narrower) than RJ-45 connectors. http://compnetworking.about.com/od/networkcables/g/bldef_rj45.htm
Switches
Switches are similar to hubs in that they allow you to connect multiple computers together on a network. You can also connect switches to routers in the same way you connect hubs.
There are several differences between hubs and switches, however, that can boost the performance of your network. The performance increase has to do with how data is transmitted between the computers on your network.
While hubs transmit data via broadcasting the data to all computers that are connected to it, switches establish a direct connection between the transmitting and receiving computers. The added benefit of this is that the bandwidth is not subdivided. If you have a 100Mbps bandwidth on your network with 2 computers connected to a switch, the total bandwidth available to both computers is 100Mbps. This means that each port on the switch has the full bandwidth dedicated to it.
Many switches also have the ability to either use half- or full-duplex (receive and transmit at the same time). Hubs are half-duplex, which means they can either receive or transmit, but not both at the same time.
As you can see you can replace existing hubs on your network with switches to increase the effective speed of your network. http://technicallyeasy.net/2008/11/what-are-hubs-and-switches/
A CD-ROM
A CD-ROM ( /ˌsiːˌdiːˈrɒm/, an acronym of "Compact Disc Read-only memory") is a pre-pressed compact disc that contains dataaccessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed bySony and Philips adapted the format to hold any form of binary data.[2]
CD-ROMs are popularly used to distribute computer software, including video games and multimedia applications, though any data can be stored (up to the capacity limit of a disc). Some CDs hold both computer data and audio with the latter capable of being played on aCD player, while data (such as software or digital video) is only usable on a computer (such as ISO 9660 format PC CD-ROMs). These are called enhanced CDs.
Even though many people use lowercase letters in this acronym, proper presentation is in all capital letters with a hyphen between CD and ROM. At the time of the technology's introduction it had more capacity than computer hard drives common at the time. The reverse is now true, with hard drives far exceeding CDs, DVDs and Blu-ray, though some experimental descendants of it such as HVDs may have more space and faster data rates than today's largest hard drive.
http://en.wikipedia.org/wiki/CD-ROM
DVD
DVD is an optical disc storage format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions.
Pre-recorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are known as DVD-ROM, because data can only be read and not written nor erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased multiple times.
DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoringAVCHD discs. DVDs containing other types of information may be referred to as DVD data discs. http://en.wikipedia.org/wiki/DVD
A modem
A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from light emitting diodes to radio. The most familiar example is a voice band modem that turns the digital data of a personal computer into modulated electrical signals in the voice frequency range of a telephone channel. These signals can be transmitted over telephone linesand demodulated by another modem at the receiver side to recover the digital data.
Modems are generally classified by the amount of data they can send in a given unit of time, usually expressed in bits per second (bit/s, or bps). Modems can alternatively be classified by their symbol rate, measured in baud. The baud unit denotes symbols per second, or the number of times per second the modem sends a new signal. For example, the ITU V.21 standard used audio frequency-shift keying, that is to say, tones of different frequencies, with two possible frequencies corresponding to two distinct symbols (or one bit per symbol), to carry 300 bits per second using 300 baud. By contrast, the original ITU V.22 standard, which was able to transmit and receive four distinct symbols (two bits per symbol), handled 1,200 bit/s by sending 600 symbols per second (600 baud) using phase shift keying.
http://en.wikipedia.org/wiki/Modem
A wireless router
A wireless router is a device that performs the functions of a router but also includes the functions of a wireless access point and anetwork switch. It is commonly used to provide access to the Internet or to some other computer network. It does not need a cabled connection. It can function in a wired LAN (local area network), in a wireless-only LAN (WLAN), or in a mixed wired/wireless network.
Most current wireless routers have the following characteristics:
§ LAN ports which function in the same manner as the ports of a network switch.
§ A WAN port which connects to a wide area network, typically one with Internet access. External destinations are accessed using this port.
§ A wireless antenna that allows connections to other wireless devices, such as NiCs, wireless repeaters, wireless access points, and wireless bridges. This antenna typically uses the Wi-Fi standard.
Some wireless routers also include a DSL or cable modem in addition to the other components.
http://en.wikipedia.org/wiki/Wireless_router
A printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces, typically wireless or Ethernet based, and can serve as a hard copy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time. In addition, a few modern printers can directly interface to electronic media such as memory cards, or to image capture devices such as digital camerasand scanners; some printers are combined with scanners or fax machines in a single unit, and can function as photocopiers. Printers that include non-printing features are sometimes called multifunction printers (MFP), multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs include printing, scanning, and copying among their many features.
http://en.wikipedia.org/wiki/Printer_(computing)
client-server
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients". The clients either run on the same computer or connect through the network.
In most common use, server is a physical computer (a computer hardware system) dedicated to running one or more such services (as a host),[1] to serve the needs of users of the other computers on the network. Depending on the computing service that it offers it could be a database server, file server, mail server, print server, web server, gaming server, or some other kind of server.
In the context of Internet Protocol (IP) networking, a server is a program that operates as a socket listener.[2]
Servers often provide essential services across a network, either to private users inside a large organization or to public users via the Internet.http://en.wikipedia.org/wiki/Server_(computing)
A peripheral
A peripheral is a device connected to a host computer, but not part of it, and is more or less dependent on the host. These are also input/output devices. It expands the host's capabilities, but does not form part of the core computer architecture.
Definition: Any auxiliary device such as a mouse, keyboard, hard drive, etc. that connects to and works with the computer in some way. Usually, the word peripheral is used to refer to a device external to the computer, like a scanner, but the devices located inside the computer case are also technically peripherals. Also Known As: external peripheral, auxiliary component
Examples: "Many of the external peripherals I own, such as my scanner and printer, connect to the peripheral ports on the back of my computer."[1]
There are three different types of peripherals: Input Output Storage
An output peripheral is an external device that provides input and output for the computer. For example RAM has a peripheral output. Some peripherals, such as the external hardrive, provide both input and output for the computer. Usually for every external device there are input and output peripherals. An example of only input peripherals, a keyboard and a mouse are input and peripherals. An example of an output peripherals are hard drives disk. The storage peripherals are also considered to be used to store information on the computer for future use.http://en.wikipedia.org/wiki/Peripheral
A desktop computer
A desktop computer is a personal computer (PC) in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers are designed to lay flat on the desk, while modern towers stand upright. Most modern desktop computers have separate screens and keyboards.
Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small. Early personal computers, like the IBM PC, were "desktop" machines, with a horizontally-oriented computer case, usually intended to have the display screen placed on top to save space on the desktop. In modern usage the word "desktop" usually refers to tower cases that are in fact more often located on the floor under the desk than on a desk.
Technically speaking desktop and tower computers are two different styles of computer case that use desk space in varying ways.[original research?] Cases intended for home theater PC systems are usually considered to be desktop cases in both senses, regardless of orientation and placement.[original research?]
http://en.wikipedia.org/wiki/Desktop_computer
Random access memory (RAM)
Random access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored datato be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are not random access, as data is read in bursts, although the name DRAM / RAM has stuck. However, many types of SRAM, ROM, OTP, and NOR flash are still random access even in a strict sense. RAM is often associated with volatile types of memory (such as DRAM memory modules), where its stored information is lost if the power is removed. Many other types of non-volatile memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash. The first RAM modules to come into the market were created in 1951 and were sold until the late 1960s and early 1970s. http://en.wikipedia.org/wiki/Random-access_memory
DDR SDRAM
Double data rate synchronous dynamic random-access memory (DDR SDRAM) is a class of memory integrated circuits used incomputers. DDR SDRAM (sometimes referred to as DDR1 SDRAM) has been superseded by DDR2 SDRAM and DDR3 SDRAM, neither of which are either forward or backward compatible with DDR SDRAM, meaning that DDR2 or DDR3 memory modules will not work in DDR equipped motherboards, and vice versa.
Compared to single data rate (SDR) SDRAM, the DDR SDRAM interface makes higher transfer rates possible by more strict control of the timing of the electrical data and clock signals. Implementations often have to use schemes such as phase-locked loops and self-calibration to reach the required timing accuracy.[1][2] The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to lower the clock frequency. One advantage of keeping the clock frequency down is that it reduces the signal integrity requirements on the circuit board connecting the memory to the controller. The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a single data rate (SDR) SDRAM running at the same clock frequency, due to this double pumping.
With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of (memory bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus, with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.
"Beginning in 1996 and concluding in June 2000, JEDEC developed the DDR (Double Data Rate) SDRAM specification (JESD79)."[3]JEDEC has set standards for data rates of DDR SDRAM, divided into two parts. The first specification is for memory chips, and the second is for memory modules.
http://en.wikipedia.org/wiki/DDR_SDRAM
A hard disk drive
A hard disk drive (HDD; also hard drive, hard disk, or disk drive)[2] is a device for storing and retrieving digital information, primarily computer data. It consists of one or more rigid (hence "hard") rapidly rotating discs (platters) coated with magnetic material, and withmagnetic heads arranged to write data to the surfaces and read it from them.
Hard drives are classified as non-volatile, random access, digital, magnetic, data storage devices. Introduced by IBM in 1956, hard disk drives have decreased in cost and physical size over the years while dramatically increasing in capacity and speed.
Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s.[3]They have maintained this position because advances in their recording capacity, cost, reliability, and speed have kept pace with the requirements for secondary storage.[3] http://en.wikipedia.org/wiki/Hard_disk_drive
a motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, planar board or, on Apple computers, the logic board.[1] It is also sometimes casually shortened to mobo. http://en.wikipedia.org/wiki/Motherboard
A video card
A video card (also called a display card, graphics card, graphics board, display adapter or graphics adapter) is an expansion card which generates a feed of output images to a display. Most video cards offer various functions such as accelerated rendering of 3Dscenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors (multi-monitor).
Video hardware can be integrated into the motherboard or (as with more recent designs) the CPU, but all modern motherboards (and some from the 1990s) provide expansion ports to which a video card can be attached. In this configuration it is sometimes referred to as a video controller or graphics controller. Modern low-end to mid-range motherboards often include a graphics chipset manufactured by the developer of the northbridge (e.g. an nForce chipset with Nvidia graphics or an Intel chipset with Intel graphics) on the motherboard. This graphics chip usually has a small quantity of embedded memory and takes some of the system's main RAM, reducing the total RAM available. This is usually called integrated graphics or on-board graphics, and is usually low in performance and undesirable for those wishing to run 3D applications. A dedicated graphics card on the other hand has its own Random Access Memory or RAM and Processor specifically for processing video images, and thus offloads this work from the CPU and system RAM. Almost all of these motherboards allow the disabling of the integrated graphics chip in BIOS, and have an AGP, PCI, or PCI Express slot for adding a higher-performance graphics card in place of the integrated graphics.http://en.wikipedia.org/wiki/Video_card
A sound card
A sound card (also known as an audio card) is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware inside the PC. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education and entertainment (games) and video projection.
Sound functionality can also be integrated onto the motherboard, using basically the same components as a plug-in card. The best plug-in cards, which use better and more expensive components, can achieve higher quality than integrated sound. The integrated sound system is often still referred to as a "sound card". http://en.wikipedia.org/wiki/Sound_card
Processor
Processor or Processing unit may refer to:
[edit]Computing
§ Central processing unit (CPU), an electronic circuit which executes computer programs, containing a processing unit and a control unit
§ Processing unit, in Von Neumann computer architecture, contains an arithmetic logic unit (ALU) and processor registers
§ Microprocessor, a CPU on one silicon chip as part of a microcomputer
§ Graphics processing unit (GPU / VPU), a dedicated graphics rendering device for a personal computer or game console
§ Physics processing unit (PPU), a dedicated microprocessor designed to handle the calculations of physics
§ Digital signal processor, a specialized microprocessor designed specifically for digital signal processing
§ Network processor, a microprocessor specifically targeted at the networking application domain
§ Front end processor, a helper processor for communication between a host computer and other devices
§ Coprocessor
§ Floating point unit
§ Data processor, a system that translates or converts between different data formats
§ Word processor, a computer application used for the production of printable material
§ Audio processor, used in studios and radio stations
http://en.wikipedia.org/wiki/Processor
CPU Cooling Fan
The components inside a computer's case, especially integrated circuits or chips, generate heat as a by-product. A build up of heat can be devastating to integrated circuits, which normally have a long life expectancy. For that reason, a combination of fans and heat sinks are used to remove excess heat from inside a computer.
Read more: Definition of CPU Cooling Fan | eHow.com http://www.ehow.com/facts_5001672_definition-cpu-cooling-fan.html#ixzz1yTsvfRcL
While a typical desktop computer case contains a large fan to remove heat that builds up inside the cabinet from various components, CPU fans are mounted directly on top of the computer's central processing unit for the sole purpose of dissipating heat on that one single chip. This is because the CPU can become extremely heated in proportion to the amount of work it is doing.
Read more: Definition of CPU Cooling Fan | eHow.com http://www.ehow.com/facts_5001672_definition-cpu-cooling-fan.html#ixzz1yTszLQd7
http://www.ehow.com/facts_5001672_definition-cpu-cooling-fan.html
CMOS
Complementary Metal-Oxide Semiconductor. The CMOS is where the basic modifiable settings of the computer (BIOS, Basic Input-Output System) (Date, time, memory) are stored. These settings are maintained when the power is turned off by a minute current, and that current is supplied by the CMOS battery
Read more: http://wiki.answers.com/Q/What_is_the_meaning_of_cmos_in_cmos_battery#ixzz1yY3p6Vxy
http://wiki.answers.com/Q/What_is_the_meaning_of_cmos_in_cmos_battery
A power supply unit
A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use a switched-mode power supply. Some power supplies have a manual selector for input voltage, while others automatically adapt to the supply voltage.
Most modern desktop personal computer power supplies conform to the ATX form factor. ATX power supplies are turned on and off by a signal from the motherboard. They also provide a signal to the motherboard to indicate when the DC power lines are correct so that the computer is able to boot up. While an ATX power supply is connected to the mains supply it provides a 5 V stand-by (5VSB) line so that the standby functions on the computer and certain peripherals are powered. The most recent ATX PSU standard is version 2.31 of mid-2008.http://en.wikipedia.org/wiki/Power_supply_unit_(computer)
Parallel ATA (PATA)
Parallel ATA (PATA), originally AT Attachment, is an interface standard for the connection of storage devices such ashard disks, floppy drives, and optical disc drives in computers. The standard is maintained by X3/INCITS committee.[1] It uses the underlying AT Attachment (ATA) and AT Attachment Packet Interface (ATAPI) standards.
The Parallel ATA standard is the result of a long history of incremental technical development, which began with the original AT Attachment interface, developed for use in early PC AT equipment. The ATA interface itself evolved in several stages from Western Digital's original Integrated Drive Electronics (IDE) interface. As a result, many near-synonyms for ATA/ATAPI and its previous incarnations are still in common informal use. After the introduction of Serial ATA in 2003, the original ATA was renamed Parallel ATA, PATA for short.
Parallel ATA cables have a maximum allowable length of only 18 in (457 mm).[2][3] Because of this limit, the technology normally appears as an internal computer storage interface. For many years ATA provided the most common and the least expensive interface for this application. It has largely been replaced by Serial ATA (SATA) in newer systems. http://en.wikipedia.org/wiki/Parallel_ATA
IDE cable
A liquid crystal display (LCD)
A liquid crystal display (LCD) is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly.
LCD displays are available to display arbitrary images (as in a general-purpose computer display) or fixed images which can be displayed or hidden, such as preset words, digits, 7-segment displays, etc., as in a digital clock. They use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements.
LCDs are used in a wide range of applications, including computer monitors, television, instrument panels, aircraft cockpit displays, signage, etc. They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. LCDs have replaced cathode ray tube (CRT) displays in most applications. They are available in a wider range of screen sizes than CRT and plasma displays, and since they do not use phosphors, they cannot suffer image burn-in. LCDs are, however, susceptible to image persistence.[1]
The LCD is more energy efficient and offers safer disposal than a CRT. Its low electrical power consumption enables it to be used inbattery-powered electronic equipment. It is an electronically modulated optical device made up of any number of segments filled withliquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome. Liquid crystals were first developed in 1888.[2] By 2008 worldwide sales of televisions with LCD screens exceeded annual sales of CRT units; the CRT became obsolete for most purposes.
http://en.wikipedia.org/wiki/Liquid_crystal_display
Cathode Ray Tube (CRT)
The cathode ray tube (CRT) is a vacuum tube containing an electron gun (a source of electrons or electron emitter) and afluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms (oscilloscope), pictures (television, computer monitor), radartargets and others. CRTs have also been used as memory devices, in which case the visible light emitted from the fluoresecent material (if any) is not intended to have significant meaning to a visual observer (though the visible pattern on the tube face may cryptically represent the stored data).
The CRT uses an evacuated glass envelope which is large, deep (i.e. long from front screen face to rear end), fairly heavy, and relatively fragile. As a matter of safety, the face is typically made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions, particularly if the CRT is used in a consumer product.
CRTs have largely been superseded by more modern display technologies such as LCD, plasma display, and OLED, which offer lower manufacturing and distribution costs.
http://en.wikipedia.org/wiki/Cathode_ray_tube
BIOS
In IBM PC compatible computers, the Basic Input Output System (In IBM PC compatible computers, the Basic Input Output System (BIOS), also known as the System BIOS or ROM BIOS ( /ˈbaɪ.oʊs/), is a de facto standard defining a firmware interface.[1] The name originated as the name of a component of CP/M (circa 1973-1974), where the BIOS was loaded from disc rather than stored as firmware on ROM (because ROMs were expensive and difficult to reprogram at the time).The BIOS software is built into the PC, and is the first code run by a PC when powered on ('boot firmware'). When the PC starts up, the first job for the BIOS is the power-on self-test, which initializes and identifies system devices such as the CPU, RAM, video display card,keyboard and mouse, hard disk drive, optical disc drive and other hardware. The BIOS then locates boot loader software held on aperipheral device (designated as a 'boot device'), such as a hard disk or a CD/DVD, and loads and executes that software, giving it control of the PC.[2] This process is known as booting, or booting up, which is short for bootstrapping.
BIOS software is stored on a non-volatile ROM chip on the motherboard. It is specifically designed to work with each particular model of computer, interfacing with various devices that make up the complementary chipset of the system. In modern computer systems theBIOS chip's contents can be rewritten without removing it from the motherboard, allowing BIOS software to be upgraded in place.
A BIOS has a user interface (UI), typically a menu system accessed by pressing a certain key on the keyboard when the PC starts. In the BIOS UI, a user can:
§ configure hardware
§ set the system clock
§ enable or disable system components
§ select which devices are eligible to be a potential boot device
§ set various password prompts, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized peripheral devices.
http://en.wikipedia.org/wiki/BIOS), also known as the System BIOS or ROM BIOS ( /ˈbaɪ.oʊs/), is a de facto standard defining a firmware interface.[1] The name originated as the name of a component of CP/M (circa 1973-1974), where the BIOS was loaded from disc rather than stored as firmware on ROM (because ROMs were expensive and difficult to reprogram at the time).
The BIOS software is built into the PC, and is the first code run by a PC when powered on ('boot firmware'). When the PC starts up, the first job for the BIOS is the power-on self-test, which initializes and identifies system devices such as the CPU, RAM, video display card,keyboard and mouse, hard disk drive, optical disc drive and other hardware. The BIOS then locates boot loader software held on aperipheral device (designated as a 'boot device'), such as a hard disk or a CD/DVD, and loads and executes that software, giving it control of the PC.[2] This process is known as booting, or booting up, which is short for bootstrapping.
BIOS software is stored on a non-volatile ROM chip on the motherboard. It is specifically designed to work with each particular model of computer, interfacing with various devices that make up the complementary chipset of the system. In modern computer systems theBIOS chip's contents can be rewritten without removing it from the motherboard, allowing BIOS software to be upgraded in place.
A BIOS has a user interface (UI), typically a menu system accessed by pressing a certain key on the keyboard when the PC starts. In the BIOS UI, a user can:
§ configure hardware
§ set the system clock
§ enable or disable system components
§ select which devices are eligible to be a potential boot device
§ set various password prompts, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized peripheral devices.
http://en.wikipedia.org/wiki/BIOS
Utility software
Utility software is system software designed to help analyze, configure, optimize or maintain a computer. A single piece of utility software is usually called a utility or tool.
Utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates. Due to this focus, utilities are often rather technical and targeted at people with an advanced level of computer knowledge - in contrast to application software, which allows users to do things like creating text documents, playing games, listening to music or viewing websites.
[edit]Utility software categories
§ Anti-virus utilities scan for computer viruses.
§ Backup utilities can make a copy of all information stored on a disk, and restore either the entire disk (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion).
§ Data compression utilities output a shorter stream or a smaller file when provided with a stream or file.
§ Disk checkers can scan operating hard drive.
§ Disk cleaners can find files that are unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full.
§ Disk compression utilities can transparently compress/uncompress the contents of a disk, increasing the capacity of the disk.
§ Disk defragmenters can detect computer files whose contents are broken across several locations on the hard disk, and move the fragments to one location to increase efficiency.
§ Disk partitions can divide an individual drive into multiple logical drives, each with its own file system which can be mounted by the operating system and treated as an individual drive.
§ Disk space analyzers for the visualization of disk space usage by getting the size for each folder (including sub folders) & files in folder or drive. showing the distribution of the used space.
§ Disk storage utilities
§ Archive utilities output a stream or a single file when provided with a directory or a set of files. Archive utilities, unlike archive suites, usually do not include compression or encryption capabilities. Some archive utilities may even have a separate un-archive utility for the reverse operation.
§ File managers provide a convenient method of performing routine data management tasks, such as deleting, renaming, cataloging, uncataloging, moving, copying, merging, generating and modifying data sets.
§ Cryptographic utilities encrypt and decrypt streams and files.
§ Hex editors directly modify the text or data of a file. These files could be data or an actual program.
§ Memory testers check for memory failures.
§ Network utilities analyze the computer's network connectivity, configure network settings, check data transfer or log events.
§ Registry cleaners clean and optimize the Windows registry by removing old registry keys that are no longer in use.
§ Screensavers were desired to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use. Contemporary screensavers are used primarily for entertainment or security.
§ System monitors for monitoring resources and performance in a computer system.
§ System profilers provide detailed information about the software installed and hardware attached to the computer. http://en.wikipedia.org/wiki/Utility_software
Electro-Static Discharge (ESD) ToolsStatic electricity is easily generated by friction on carpets, tile flooring, clothing, hair, fabric, and etc. The friction of moving air alone will charge suspended parties and cause the buildup of static electrical charges on people and objects in the environment. Grounded antistatic work mats used electrostatic electricity. Examples of ESD Tools:
Anti-static wrist strap
Anti-static wrist strap-used to prevent ESD damage to computer equipment.
Anti-static mat
Anti-static - used to stand on or place hardware on to prevent static electricity from building up.
Hand ToolsA hand tool is a device for performing work on a material or a physical system using only hands. The hands tools can be manually used employing force, or electrically powered, using electrical current. Examples of Hand Tools:
Flat head screwdriver
Flat head screwdriver - used to loosen or tighten slotted screws.
Philips head screwdriver
Philips head screwdriver - used to loosen or tighten cross-head screws.
Torx screwdriver
Torx screwdriver - used to loosen or tighten screws that have a star-like depression on the top, a feature that is mainly found laptop.
Hex driver
Hex driver - sometimes called a nut driver, is used to tighten nuts in the same way that a screwdriver tightens screws.
Needle-nose plier
Needle-nose plier - used to hold small parts.
Wire cutter
Wire cutter - used to strip and cut wires.
Tweezers
Tweezers - used to manipulate small parts.
Part retriever
Part retriever - used to retrieve parts from location that are too small for your hand to fit.
Flashlight
Flashlight - used to light up areas that you cannot see well.
Cleaning ToolsHaving the appropriate cleaning tools is essential when maintaining or repairing computers. Using these tools ensures the computer components are not damage during cleaning. Examples.
Lint-free cloth
Lint-free cloth - used to clean different computer components without scratching or leaving debris.
Compressed air
Compressed air - used to blow away dust and debris from different computer parts without touching the components.
Cable ties
Cable ties - used to bundle cables neatly inside and outside of a computer.
Parts organizer
Parts organized - used to hold screw, jumpers, fasteners and other small parts and prevents them from getting mixed together.
Diagnostic ToolsComputers are easier to use and more dependable with each new generation of hardware and operating system update, but that doesn't mean they're problem-free. Here's the most popularb tools for diagnosing your computer problems:
Multimeter
Multimeter -used to test the integrity of circuits and the quality of electricity in computer components.
Loopback Adapter
Loopback Adapter - used to test the functionality of computer ports.
PC Tools for Software and Hardware Trouble Shooting.These are the PC Tools and Components that will be used in PC Hardware and Software Trouble Shootings.
A lens
A lens is an optical device which transmits and refracts light, converging or diverging the beam.[citation needed] A simple lensconsists of a single optical element. A compound lens is an array of simple lenses (elements) with a common axis; the use of multiple elements allows more optical aberrations to be corrected than is possible with a single element. Lenses are typically made of glass or transparent plastic. Elements which refract electromagnetic radiation outside the visual spectrum are also called lenses: for instance, a microwave lens can be made from paraffin wax.http://en.wikipedia.org/wiki/Lens_(optics)
A ruler
A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing and engineering/building to measure distances and/or to rule straight lines. Strictly speaking, the ruler is essentially a straightedge used to rule lines[citation needed], but typically the ruler also contains calibrated lines to measure distances.[1] http://en.wikipedia.org/wiki/Ruler
A T-square
A T-square is a technical drawing instrument used by draftsmen primarily as a guide for drawing horizontal lines on a drafting table. It may also guide a set square to draw vertical or diagonal lines. Its name comes from the general shape of the instrument where the horizontal member of the T slides on the side of the drafting table. T-squares come in varying sizes, common lengths being 18", 24", 30", 36" and 42".[citation needed]
T-squares are also used to measure and cut drywall. Drywall T-squares are typically made of aluminium and have a 48-inch (1,220 mm) long tongue.
Higher-end table saws are often equipped with T-square fences. These table saw fences are attached to a rail only on the front side of the table unlike traditional fences which clamp to both the front and the rear of the table.http://en.wikipedia.org/wiki/T-square
Steel rules
Steel rules come in rigid and flexible versions. While their primary purpose is accurate measurement, they can also be used as guides for laying out lines, and if rigid enough, for cutting. The thinner, more flexible rules can also be used to measure rounded or cambered work.
The differences in the prices of rules result from the various production methods, which also determine accuracy and legibility. Most rules are made by cutting the required length from a roll of band spring steel, with etched graduations. Rules made by this method are adequate for most applications and reasonably priced.
Higher-priced rules are cut, not stamped, from plate steel (stamping would cause the material to warp), and the edges are ground. Graduations are machined, much deeper than etched graduations, longer-lasting, and easier to read in poor light. http://www.fine-tools.com/mass.htm
A protractor
In geometry, a protractor is a square, circular or semicircular tool, typically in transparent perspex, for measuring angles. The units of measurement utilized are usually degrees (°).
They are used for a variety of mechanical and engineering-related applications, but perhaps the most common use is in geometry lessons in schools.
Some protractors are simple half-discs. More advanced protractors, such as the bevel protractor, have one or two swinging arms, which can be used to help measure the angle.
http://en.wikipedia.org/wiki/Protractor
An electronic calculator
An electronic calculator is a small, portable, usually inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.
The first solid state electronic calculator was created in the 1960s, building on the history of tools such as the abacus, developed around 2000 BC; and the mechanical calculator, developed in the 17th century. It was developed in parallel with the analog computers of the day.
Pocket-sized devices became available in the 1970s, especially after the invention of the microprocessor developed serendipitously byIntel for a Busicom calculator.
Modern electronic calculators vary from cheap, give-away, credit-card sized models to sturdy desktop models with built-in printers. They became popular in the mid-1970s as integrated circuits made their size and cost small. By the end of that decade, calculator prices had reduced to a point where a basic calculator was affordable to most and they became common in schools. http://en.wikipedia.org/wiki/Calculator
A multimeter
A multimeter or a multitester, also known as a VOM (Volt-Ohm meter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current andresistance. Multimeters may use analog or digital circuits--analog multimeters (AMM) and digital multimeters (often abbreviatedDMM or DVOM.) Analog instruments are usually based on a microammeter whose pointer moves over a scale calibrated for all the different measurements that can be made; digital instruments usually display digits, but may display a bar of a length proportional to the quantity being measured.
A multimeter can be a hand-held device useful for basic fault finding and field service work or a bench instrument which can measure to a very high degree of accuracy. They can be used to troubleshoot electrical problems in a wide array of industrial and household devices such as electronic equipment, motor controls, domestic appliances, power supplies, and wiring systems. http://en.wikipedia.org/wiki/Multimeter
An eraser
An eraser (US) or rubber (elsewhere) is an article of stationery that is used for removing pencil markings. Erasers have a rubbery consistency and are often pink or white. Some pencils have an eraser on one end. Typical erasers are made fromsynthetic rubber, but more expensive or specialized erasers are vinyl, plastic, or gum-like materials. Cheaper erasers can be made out of synthetic soy-based gum.
An eraser can be used of cleaning the RAM, a memory chip of the PC.
http://www.nlm.nih.gov/medlineplus/ency/article/002816.htm
paint brush
brush 1 (brsh)
n.
1. a. A device consisting of bristles fastened into a handle, used in scrubbing, polishing, or painting.
b. The act of using this device.
2. A light touch in passing; a graze.
3. An instance of contact with something undesirable or dangerous: a brush with the law; a brush with death.
4. A bushy tail: the brush of a fox.
5. A sliding connection completing a circuit between a fixed and a moving conductor.
6. A snub; a brushoff.
http://www.thefreedictionary.com/Paint+brush
A vacuum
A vacuum is a space devoid of air or matter, or a tool that uses suction to clean.(noun)
1. An example of a vacuum is a space with nothing in it.
2. An example of a vacuum is something used to clean up dirt on a floor.
To vacuum is to clean using a tool that sucks dirt or other elements into a storage container. (verb)
An example of vacuum is to clean the dirt off the carpet using a vacuum cleaner.
http://www.yourdictionary.com/vacuum
A soldering gun
A soldering gun is an approximately pistol-shaped tool for soldering metals using tin-based solder to achieve a strong mechanical bond with good electrical contact. The tool has a trigger-style switch so it can be easily operated with one hand. The body of the tool contains a transformer with a primary winding connected to mains electricity when the trigger is pressed, and an incomplete single-turn secondary winding of thick copper with very low resistance. A soldering tip, made of a loop of thinner copper wire, is secured to the end of the transformer secondary by screws, completing the secondary winding. When the primary of the transformer is energized, several hundred amperes of current flow through the secondary and very rapidly heat the copper tip. Since the tip has a much higher resistance than the rest of the tubular copper winding, the tip, used for soldering, gets very hot while the remainder of the secondary warms much less. A tap on the primary winding is often used to light a pilot lamp which also provides illumination of the workpiece. http://en.wikipedia.org/wiki/Soldering_gun
Pliers
Pliers are a hand tool used to hold objects firmly, for bending, or physical compression. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longerhandles on the other side. This arrangement creates a mechanical advantage, allowing the force of the hand's grip to be amplified and focused on an object with precision. The jaws can also be used to manipulate objects too small or unwieldy to be manipulated with the fingers. http://en.wikipedia.org/wiki/Pliers
Diagonal pliers
Diagonal pliers (or wire cutters or diagonal cutting pliers) are pliers intended for the cutting of wire (they are generally not used to grab or turn anything). The plane defined by the cutting edges of the jaws intersects the joint rivet at an angle or "on a diagonal", hence the name. Instead of using a shearing action as with scissors, they cut by indenting and wedging the wire apart. The jaw edges are ground to a symmetrical "V" shape; thus the two jaws can be visualized to form the letter "X", as seen end-on when fully occluded. The pliers are made of tempered steel with inductive heating and quenching often used to selectively harden the jaws.
http://en.wikipedia.org/wiki/Diagonal_pliers
A Phillips screw driver
A Phillips screw driver is primarily used to fasten and unfasten screws with a star-like hole in their heads.
Read more: http://wiki.answers.com/Q/What_is_the_use_of_a_Philips_screwdriver#ixzz1yYGur1jE
http://wiki.answers.com/Q/What_is_the_use_of_a_Philips_screwdriver
A screwdriver
A screwdriver is a tool for driving screws or bolts with special slots, and sometimes for rotating other machine elements with the mating drive system. The screwdriver is made up of a head or tip, which engages with a screw, a mechanism to apply torque byrotating the tip, and some way to position and support the screwdriver. A typical hand screwdriver comprises an approximately cylindrical handle of a size and shape to be held by a human hand, and an axial shaft fixed to the handle, the tip of which is shaped to fit a particular type of screw. The handle and shaft allow the screwdriver to be positioned and supported and, when rotated, to apply torque. Screwdrivers are made in a variety of shapes, and the tip can be rotated manually or by an electric motor or other motor. http://en.wikipedia.org/wiki/Screwdriver
The flat head is also one of the most abused tools, often substituted for any number of other tools that might not be available. The fact is the flat head screwdriver is quite useful for more than tightening screws. Used for light prying, scraping, nudging or holding it can be pretty versatile. Treat it too badly, though, and it'll snap, leaving you with a fishing weight in your toolbox. http://autorepair.about.com/od/tools/a/tools_flathed.htm
Goggles or safety glasses
Goggles or safety glasses are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and in woodworking. They are often used in snow sports as well, and in swimming. Goggles are often worn when using power tools such as drills or chainsaws to prevent flying particles from damaging the eyes. Many types of goggles are available as prescription goggles for those with vision problems. http://en.wikipedia.org/wiki/Goggles
A glove
A glove (Middle English from Old English glof) is a garment covering the whole hand. Gloves have separate sheaths or openings for eachfinger and the thumb; if there is an opening but no covering sheath for each finger they are called "fingerless gloves". Fingerless gloves with one large opening rather than individual openings for each finger are sometimes called gauntlets. Gloves which cover the entire hand or fist but do not have separate finger openings or sheaths are called mittens. Mittens are warmer than gloves made of the same material because fingers maintain their warmth better when they are in contact with each other. Reduced surface area reduces heat loss. http://en.wikipedia.org/wiki/Glove
LAN tester
· What are the features of LAN tester?
· How do you establish LAN to LAN connection?
The traffic has to go through a router to connect one network to another. Read More
· What does a LAN does?
A "LAN" stands for Local Area Network. It's just what it sounds like. A group of private computers that are connected by a common private network. If you have 2 computers in your home, and they are... Read More
· What is a LAN?
a LAN is a Local Area Network Answer. A LAN is the short abbreviation for Local Area Network. In a LAN you usually have many computers connected together using ehternet, Wifi, etc. The computers in... Read More
· What are LANs?
LAN stands for Local Area Network. A computing term for a method of connecting computers, generally using wires, and generally in the one building. Read More
http://wiki.answers.com/Q/What_is_LAN_tester
An antistatic wrist strap
An antistatic wrist strap, ESD wrist strap, or ground bracelet is an antistatic device used to safely ground a person working on very sensitive electronic equipment, to prevent the buildup of static electricity on their body, which can result in electrostatic discharge (ESD). It is used in the electronics industry by workers working on electronic devices which can be damaged by ESD, and also sometimes by people working around explosives, to prevent electric sparks which could set off an explosion. It consists of a stretchy band offabric with fine conductive fibers woven into it, attached to a wire with a clip on the end to connect it to a ground conductor. The fibers are usually made of carbon or carbon-filled rubber, and the strap is bound with a stainless steel clasp or plate. They are usually used in conjunction with an antistatic mat on the workbench, or a special static-dissipating plastic laminate on the workbench surface.http://en.wikipedia.org/wiki/Antistatic_wrist_strap
A crimping tool
A crimping tool is a tool designed to crimp or connect a connector to the end of a cable. For example, network cables and phone cables are created using a crimping tool to connect the RJ-45 and RJ-11 connectors to the end of the cable. In the picture to the right, is an example of what a crimping tool looks like. This example shows a tool capable of crimping both RJ-11 and RJ-45 connectors.http://www.computerhope.com/jargon/c/crimp.htm
Sharp Pointed Tweezers
The Tweezerman Pointed Tweezers feature perfectly aligned, hand filed tips made from 100 stainless steel. The fine, precision design makes eliminating even the most stubborn stray hairs a cinch.Caution: Tweezers are very sharp. Use with care. Keep out of the reach of children.Tweeze in the direction of hair growth, after a hot shower, or use a hot wash cloth to open pores. For ingrown hairs, cleanse skin and disinfect the tips of the tweezers with alcohol. After any work under the skin, clean area with hydrogen peroxide. Always replace protective cap on tweezer tips. http://reviews.sephora.com/8723/P63915/reviews.htm
A soldering iron
A soldering iron is a hand tool used in soldering. It supplies heat to melt the solder so that it can flow into the joint between two workpieces.
A soldering iron is composed of a heated metal tip and an insulated handle. Heating is often achieved electrically, by passing an electric current (supplied through an electrical cord or battery cables) through a resistive heating element. Portable irons can be heated by combustion of gas stored in a small tank, often using a catalytic heater rather than a flame. Simple irons less commonly used than in the past were simply a large copper bit on a handle, heated in a flame.
Soldering irons are most often used for installation, repairs, and limited production work in electronics assembly. High-volume production lines use other soldering methods.[1] Large irons may be used for soldering joints in sheet metal objects. Less common uses includepyrography (burning designs into wood) and plastic welding.http://en.wikipedia.org/wiki/Soldering_iron
An operating system
An operating system is a program designed to run other programs on a computer. A computer’s operating system is its most important program. It is considered the backbone of a computer, managing both software and hardware resources. Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays. They also manage files on computer hard drives and control peripherals, like printers and scanners.http://www.wisegeek.com/what-is-an-operating-system.htm
An application program
An application program (sometimes shortened to application) is any program designed to perform a specific function directly for the user or, in some cases, for another application program. Examples of application programs include word processors; database programs; Web browsers; development tools; drawing, paint, and image editing programs; and communication programs. Application programs use the services of the computer's operating system and other supporting programs. The formal requests for services and means of communicating with other programs that a programmer uses in writing an application program is called the application program interface (API).http://searchsoftwarequality.techtarget.com/definition/application-program
An oscilloscope
An oscilloscope, previously called an oscillograph, and informally known as a scope, CRO (for cathode-ray oscilloscope), or DSO (for the more modern digital storage oscilloscope), is a type of electronic test instrument that allows observation of constantly varying signalvoltages, usually as a two-dimensional graph of one or more electrical potential differences using the vertical or 'Y' axis, plotted as a function of time (horizontal or 'x' axis). Many signals, for example sound, can be converted to voltages and displayed this way. Signals are often periodic and repeat constantly, so that multiple samples of a signal which is actually varying with time are displayed as a steady picture. Many oscilloscopes (storage oscilloscopes) can also capture non-repeating waveforms for a specified time, and show a steady display of the captured segment.
Oscilloscopes are commonly used to observe the exact wave shape of an electrical signal. Oscilloscopes are usually calibrated so that voltage and time can be read as well as is possible by eye. This allows the measurement of, for example, peak-to-peak voltage of a waveform, the frequency of periodic signals, the time between pulses, the time taken for a to rise to full amplitude (rise time), and relative timing of several related signals.[1]
Oscilloscopes are used in the sciences, medicine, engineering, and telecommunications industry. General-purpose instruments are used for maintenance of electronic equipment and laboratory work. Special-purpose oscilloscopes may be used for such purposes as analyzing an automotive ignition system, or to display the waveform of the heartbeat as an electrocardiogram. Some computer sound software allows the sound being listened to to be displayed on the screen as by an oscilloscope.
Before the advent of digital electronics oscilloscopes used cathode ray tubes as their display element (hence were commonly referred to as CROs) and linear amplifiers for signal processing. More advanced storage oscilloscopes used special storage CRTs to maintain a steady display of a single brief signal. CROs were later largely superseded by digital storage oscilloscopes (DSOs) with thin panel displays, fast analog-to-digital converters and digital signal processors. DSOs without integrated displays (sometimes known as digitisers) are available at lower cost, and use a general-purpose digital computer to process and display waveforms. http://en.wikipedia.org/wiki/Oscilloscope
A hub
A hub is a piece of hardware that contains several ethernet ports that connects several computers. Connecting a hub to a network is very easy. You can simply connect a hub to your router, and then several computers to the hub. The IP addresses of the computers that are connected to the hub are assigned by the router it is connected to.
Hubs work by broadcasting data to all computers that are connected to it. When a computer or program makes a request for information from another computer, the originating computer sends (broadcasts) the request to the hub. The hub will then brodcast the request to all computers that are connect to it. When the destination computer receives the request, it sends the information back to the hub. Once again the hub broadcasts the information to all computers, with only the requesting computer acting on the information.
The downside to this type of connection is that the bandwidth is subdivided between the number of computers that are connected to the hub. If you have a 100Mbps connection, and 2 computers connected to the hub, then the bandwidth available to each computer is 50Mbps. With 4 computers, the bandwidth drops to 25Mbps.
An alternative to hubs are switches.
RJ45
RJ45 may refer to:
§ RJ45 (telecommunications), a connector standard for telephone cables
§ RJ45 (computers), a connector for computer network (Ethernet) cables
§ Modular connectors come in four sizes: 4-, 6-, 8-, and 10-position, where a position is a location for a contact. Not all of the positions may have contacts installed. When contacts are omitted, they are typically done so from the outermost pair of contacts inward, such that the number of contacts is almost always an even number. The insulating plastic bodies of 4P and 6P connectors have different widths, whereas 8P or 10P connectors share an even larger body width. The connector body positions with omitted contacts or contacts unattached to wires are unused for the electrical connection, but ensure that the plug fits correctly. For instance, RJ11 cables often have connectors with 6 positions and 4 contacts, to which are attached just 2 wires.
§ The connectors are designated with two numbers that represent the quantity of positions and contacts, with each number followed by a "P" and "C", respectively: for example, "6P2C" for a connector having 6 positions and 2 contacts. Alternate designations omit the "P" and "C" while separating the position and contact quantities with either an "x" ("6x2") or a slash ("6/2").
§ Internally, the contacts have sharp prongs that when crimped, pierce the insulation and connect with the wire conductor, a mechanism known as insulation displacement. Ethernet cables, in particular, may have solid or stranded wire conductors and the sharp prongs are different in the 8P8C connectors made for each type of wire. A modular plug for solid (single strand) wire often has three slightly splayed prongs on each contact to securely surround and grip the conductor. Modular plugs for stranded or tinsel wire have prongs that are designed to connect to multiple wire strands. Connector plugs are designed for either solid or stranded wire; a plug for one wire type might not make reliable contact when crimped to a cable with wires of the other type.
§ The dimensions of the connectors are such that a plug can be inserted into a jack that has more positions than the plug, leaving the jack's outermost contacts unconnected. However, not all plugs from all manufacturers have this capability, and some jack manufacturers warn that their jacks are not designed to accept smaller plugs without damage. If an inserted plug lacks contact slots at the outermost extremes, it may permanently deform the outmost contacts of an incompatible jack.
§ The contact positions are numbered sequentially starting from 1. When viewed head-on with the retention mechanism on the bottom, jacks will have contact position number 1 on the left and plugs will have it on the right. Contacts are numbered by the contact position. For example, on a 6-position, 2-contact plug, where the outermost four positions do not have contacts, the innermost two contacts are numbered 3 and 4.
§ Some modular connectors are indexed: their dimensions are intentionally non-standard, preventing connections with connectors of standard dimensions. The means of indexing may be non-standard cross-section dimensions or shapes, retention mechanism dimensions, or retention mechanism quantity. For example, a Modified Modular Jack (MMJ) using an offset latching tab was developed by Digital Equipment Corporation (DEC) to prevent accidental interchange of data and telephone cables.
http://en.wikipedia.org/wiki/RJ45
RJ45
RJ45 is a standard type of connector for network cables. RJ45 connectors are most commonly seen with Ethernet cables and networks.
RJ45 connectors feature eight pins to which the wire strands of a cable interface electrically. Standard RJ-45 pinouts define the arrangement of the individual wires needed when attaching connectors to a cable.
Several other kinds of connectors closely resemble RJ45 and can be easily confused for each other. The RJ-11 connectors used with telephone cables, for example, are only slightly smaller (narrower) than RJ-45 connectors. http://compnetworking.about.com/od/networkcables/g/bldef_rj45.htm
Switches
Switches are similar to hubs in that they allow you to connect multiple computers together on a network. You can also connect switches to routers in the same way you connect hubs.
There are several differences between hubs and switches, however, that can boost the performance of your network. The performance increase has to do with how data is transmitted between the computers on your network.
While hubs transmit data via broadcasting the data to all computers that are connected to it, switches establish a direct connection between the transmitting and receiving computers. The added benefit of this is that the bandwidth is not subdivided. If you have a 100Mbps bandwidth on your network with 2 computers connected to a switch, the total bandwidth available to both computers is 100Mbps. This means that each port on the switch has the full bandwidth dedicated to it.
Many switches also have the ability to either use half- or full-duplex (receive and transmit at the same time). Hubs are half-duplex, which means they can either receive or transmit, but not both at the same time.
As you can see you can replace existing hubs on your network with switches to increase the effective speed of your network. http://technicallyeasy.net/2008/11/what-are-hubs-and-switches/
A CD-ROM
A CD-ROM ( /ˌsiːˌdiːˈrɒm/, an acronym of "Compact Disc Read-only memory") is a pre-pressed compact disc that contains dataaccessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed bySony and Philips adapted the format to hold any form of binary data.[2]
CD-ROMs are popularly used to distribute computer software, including video games and multimedia applications, though any data can be stored (up to the capacity limit of a disc). Some CDs hold both computer data and audio with the latter capable of being played on aCD player, while data (such as software or digital video) is only usable on a computer (such as ISO 9660 format PC CD-ROMs). These are called enhanced CDs.
Even though many people use lowercase letters in this acronym, proper presentation is in all capital letters with a hyphen between CD and ROM. At the time of the technology's introduction it had more capacity than computer hard drives common at the time. The reverse is now true, with hard drives far exceeding CDs, DVDs and Blu-ray, though some experimental descendants of it such as HVDs may have more space and faster data rates than today's largest hard drive.
http://en.wikipedia.org/wiki/CD-ROM
DVD
DVD is an optical disc storage format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions.
Pre-recorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are known as DVD-ROM, because data can only be read and not written nor erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased multiple times.
DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoringAVCHD discs. DVDs containing other types of information may be referred to as DVD data discs. http://en.wikipedia.org/wiki/DVD
A modem
A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from light emitting diodes to radio. The most familiar example is a voice band modem that turns the digital data of a personal computer into modulated electrical signals in the voice frequency range of a telephone channel. These signals can be transmitted over telephone linesand demodulated by another modem at the receiver side to recover the digital data.
Modems are generally classified by the amount of data they can send in a given unit of time, usually expressed in bits per second (bit/s, or bps). Modems can alternatively be classified by their symbol rate, measured in baud. The baud unit denotes symbols per second, or the number of times per second the modem sends a new signal. For example, the ITU V.21 standard used audio frequency-shift keying, that is to say, tones of different frequencies, with two possible frequencies corresponding to two distinct symbols (or one bit per symbol), to carry 300 bits per second using 300 baud. By contrast, the original ITU V.22 standard, which was able to transmit and receive four distinct symbols (two bits per symbol), handled 1,200 bit/s by sending 600 symbols per second (600 baud) using phase shift keying.
http://en.wikipedia.org/wiki/Modem
A wireless router
A wireless router is a device that performs the functions of a router but also includes the functions of a wireless access point and anetwork switch. It is commonly used to provide access to the Internet or to some other computer network. It does not need a cabled connection. It can function in a wired LAN (local area network), in a wireless-only LAN (WLAN), or in a mixed wired/wireless network.
Most current wireless routers have the following characteristics:
§ LAN ports which function in the same manner as the ports of a network switch.
§ A WAN port which connects to a wide area network, typically one with Internet access. External destinations are accessed using this port.
§ A wireless antenna that allows connections to other wireless devices, such as NiCs, wireless repeaters, wireless access points, and wireless bridges. This antenna typically uses the Wi-Fi standard.
Some wireless routers also include a DSL or cable modem in addition to the other components.
http://en.wikipedia.org/wiki/Wireless_router
A printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces, typically wireless or Ethernet based, and can serve as a hard copy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time. In addition, a few modern printers can directly interface to electronic media such as memory cards, or to image capture devices such as digital camerasand scanners; some printers are combined with scanners or fax machines in a single unit, and can function as photocopiers. Printers that include non-printing features are sometimes called multifunction printers (MFP), multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs include printing, scanning, and copying among their many features.
http://en.wikipedia.org/wiki/Printer_(computing)
client-server
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients". The clients either run on the same computer or connect through the network.
In most common use, server is a physical computer (a computer hardware system) dedicated to running one or more such services (as a host),[1] to serve the needs of users of the other computers on the network. Depending on the computing service that it offers it could be a database server, file server, mail server, print server, web server, gaming server, or some other kind of server.
In the context of Internet Protocol (IP) networking, a server is a program that operates as a socket listener.[2]
Servers often provide essential services across a network, either to private users inside a large organization or to public users via the Internet.http://en.wikipedia.org/wiki/Server_(computing)
A peripheral
A peripheral is a device connected to a host computer, but not part of it, and is more or less dependent on the host. These are also input/output devices. It expands the host's capabilities, but does not form part of the core computer architecture.
Definition: Any auxiliary device such as a mouse, keyboard, hard drive, etc. that connects to and works with the computer in some way. Usually, the word peripheral is used to refer to a device external to the computer, like a scanner, but the devices located inside the computer case are also technically peripherals. Also Known As: external peripheral, auxiliary component
Examples: "Many of the external peripherals I own, such as my scanner and printer, connect to the peripheral ports on the back of my computer."[1]
There are three different types of peripherals: Input Output Storage
An output peripheral is an external device that provides input and output for the computer. For example RAM has a peripheral output. Some peripherals, such as the external hardrive, provide both input and output for the computer. Usually for every external device there are input and output peripherals. An example of only input peripherals, a keyboard and a mouse are input and peripherals. An example of an output peripherals are hard drives disk. The storage peripherals are also considered to be used to store information on the computer for future use.http://en.wikipedia.org/wiki/Peripheral
A desktop computer
A desktop computer is a personal computer (PC) in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers are designed to lay flat on the desk, while modern towers stand upright. Most modern desktop computers have separate screens and keyboards.
Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small. Early personal computers, like the IBM PC, were "desktop" machines, with a horizontally-oriented computer case, usually intended to have the display screen placed on top to save space on the desktop. In modern usage the word "desktop" usually refers to tower cases that are in fact more often located on the floor under the desk than on a desk.
Technically speaking desktop and tower computers are two different styles of computer case that use desk space in varying ways.[original research?] Cases intended for home theater PC systems are usually considered to be desktop cases in both senses, regardless of orientation and placement.[original research?]
http://en.wikipedia.org/wiki/Desktop_computer
Random access memory (RAM)
Random access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored datato be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are not random access, as data is read in bursts, although the name DRAM / RAM has stuck. However, many types of SRAM, ROM, OTP, and NOR flash are still random access even in a strict sense. RAM is often associated with volatile types of memory (such as DRAM memory modules), where its stored information is lost if the power is removed. Many other types of non-volatile memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash. The first RAM modules to come into the market were created in 1951 and were sold until the late 1960s and early 1970s. http://en.wikipedia.org/wiki/Random-access_memory
DDR SDRAM
Double data rate synchronous dynamic random-access memory (DDR SDRAM) is a class of memory integrated circuits used incomputers. DDR SDRAM (sometimes referred to as DDR1 SDRAM) has been superseded by DDR2 SDRAM and DDR3 SDRAM, neither of which are either forward or backward compatible with DDR SDRAM, meaning that DDR2 or DDR3 memory modules will not work in DDR equipped motherboards, and vice versa.
Compared to single data rate (SDR) SDRAM, the DDR SDRAM interface makes higher transfer rates possible by more strict control of the timing of the electrical data and clock signals. Implementations often have to use schemes such as phase-locked loops and self-calibration to reach the required timing accuracy.[1][2] The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to lower the clock frequency. One advantage of keeping the clock frequency down is that it reduces the signal integrity requirements on the circuit board connecting the memory to the controller. The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a single data rate (SDR) SDRAM running at the same clock frequency, due to this double pumping.
With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of (memory bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus, with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.
"Beginning in 1996 and concluding in June 2000, JEDEC developed the DDR (Double Data Rate) SDRAM specification (JESD79)."[3]JEDEC has set standards for data rates of DDR SDRAM, divided into two parts. The first specification is for memory chips, and the second is for memory modules.
http://en.wikipedia.org/wiki/DDR_SDRAM
A hard disk drive
A hard disk drive (HDD; also hard drive, hard disk, or disk drive)[2] is a device for storing and retrieving digital information, primarily computer data. It consists of one or more rigid (hence "hard") rapidly rotating discs (platters) coated with magnetic material, and withmagnetic heads arranged to write data to the surfaces and read it from them.
Hard drives are classified as non-volatile, random access, digital, magnetic, data storage devices. Introduced by IBM in 1956, hard disk drives have decreased in cost and physical size over the years while dramatically increasing in capacity and speed.
Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s.[3]They have maintained this position because advances in their recording capacity, cost, reliability, and speed have kept pace with the requirements for secondary storage.[3] http://en.wikipedia.org/wiki/Hard_disk_drive
a motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, planar board or, on Apple computers, the logic board.[1] It is also sometimes casually shortened to mobo. http://en.wikipedia.org/wiki/Motherboard
A video card
A video card (also called a display card, graphics card, graphics board, display adapter or graphics adapter) is an expansion card which generates a feed of output images to a display. Most video cards offer various functions such as accelerated rendering of 3Dscenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors (multi-monitor).
Video hardware can be integrated into the motherboard or (as with more recent designs) the CPU, but all modern motherboards (and some from the 1990s) provide expansion ports to which a video card can be attached. In this configuration it is sometimes referred to as a video controller or graphics controller. Modern low-end to mid-range motherboards often include a graphics chipset manufactured by the developer of the northbridge (e.g. an nForce chipset with Nvidia graphics or an Intel chipset with Intel graphics) on the motherboard. This graphics chip usually has a small quantity of embedded memory and takes some of the system's main RAM, reducing the total RAM available. This is usually called integrated graphics or on-board graphics, and is usually low in performance and undesirable for those wishing to run 3D applications. A dedicated graphics card on the other hand has its own Random Access Memory or RAM and Processor specifically for processing video images, and thus offloads this work from the CPU and system RAM. Almost all of these motherboards allow the disabling of the integrated graphics chip in BIOS, and have an AGP, PCI, or PCI Express slot for adding a higher-performance graphics card in place of the integrated graphics.http://en.wikipedia.org/wiki/Video_card
A sound card
A sound card (also known as an audio card) is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware inside the PC. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education and entertainment (games) and video projection.
Sound functionality can also be integrated onto the motherboard, using basically the same components as a plug-in card. The best plug-in cards, which use better and more expensive components, can achieve higher quality than integrated sound. The integrated sound system is often still referred to as a "sound card". http://en.wikipedia.org/wiki/Sound_card
Processor
Processor or Processing unit may refer to:
[edit]Computing
§ Central processing unit (CPU), an electronic circuit which executes computer programs, containing a processing unit and a control unit
§ Processing unit, in Von Neumann computer architecture, contains an arithmetic logic unit (ALU) and processor registers
§ Microprocessor, a CPU on one silicon chip as part of a microcomputer
§ Graphics processing unit (GPU / VPU), a dedicated graphics rendering device for a personal computer or game console
§ Physics processing unit (PPU), a dedicated microprocessor designed to handle the calculations of physics
§ Digital signal processor, a specialized microprocessor designed specifically for digital signal processing
§ Network processor, a microprocessor specifically targeted at the networking application domain
§ Front end processor, a helper processor for communication between a host computer and other devices
§ Coprocessor
§ Floating point unit
§ Data processor, a system that translates or converts between different data formats
§ Word processor, a computer application used for the production of printable material
§ Audio processor, used in studios and radio stations
http://en.wikipedia.org/wiki/Processor
CPU Cooling Fan
The components inside a computer's case, especially integrated circuits or chips, generate heat as a by-product. A build up of heat can be devastating to integrated circuits, which normally have a long life expectancy. For that reason, a combination of fans and heat sinks are used to remove excess heat from inside a computer.
Read more: Definition of CPU Cooling Fan | eHow.com http://www.ehow.com/facts_5001672_definition-cpu-cooling-fan.html#ixzz1yTsvfRcL
While a typical desktop computer case contains a large fan to remove heat that builds up inside the cabinet from various components, CPU fans are mounted directly on top of the computer's central processing unit for the sole purpose of dissipating heat on that one single chip. This is because the CPU can become extremely heated in proportion to the amount of work it is doing.
Read more: Definition of CPU Cooling Fan | eHow.com http://www.ehow.com/facts_5001672_definition-cpu-cooling-fan.html#ixzz1yTszLQd7
http://www.ehow.com/facts_5001672_definition-cpu-cooling-fan.html
CMOS
Complementary Metal-Oxide Semiconductor. The CMOS is where the basic modifiable settings of the computer (BIOS, Basic Input-Output System) (Date, time, memory) are stored. These settings are maintained when the power is turned off by a minute current, and that current is supplied by the CMOS battery
Read more: http://wiki.answers.com/Q/What_is_the_meaning_of_cmos_in_cmos_battery#ixzz1yY3p6Vxy
http://wiki.answers.com/Q/What_is_the_meaning_of_cmos_in_cmos_battery
A power supply unit
A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use a switched-mode power supply. Some power supplies have a manual selector for input voltage, while others automatically adapt to the supply voltage.
Most modern desktop personal computer power supplies conform to the ATX form factor. ATX power supplies are turned on and off by a signal from the motherboard. They also provide a signal to the motherboard to indicate when the DC power lines are correct so that the computer is able to boot up. While an ATX power supply is connected to the mains supply it provides a 5 V stand-by (5VSB) line so that the standby functions on the computer and certain peripherals are powered. The most recent ATX PSU standard is version 2.31 of mid-2008.http://en.wikipedia.org/wiki/Power_supply_unit_(computer)
Parallel ATA (PATA)
Parallel ATA (PATA), originally AT Attachment, is an interface standard for the connection of storage devices such ashard disks, floppy drives, and optical disc drives in computers. The standard is maintained by X3/INCITS committee.[1] It uses the underlying AT Attachment (ATA) and AT Attachment Packet Interface (ATAPI) standards.
The Parallel ATA standard is the result of a long history of incremental technical development, which began with the original AT Attachment interface, developed for use in early PC AT equipment. The ATA interface itself evolved in several stages from Western Digital's original Integrated Drive Electronics (IDE) interface. As a result, many near-synonyms for ATA/ATAPI and its previous incarnations are still in common informal use. After the introduction of Serial ATA in 2003, the original ATA was renamed Parallel ATA, PATA for short.
Parallel ATA cables have a maximum allowable length of only 18 in (457 mm).[2][3] Because of this limit, the technology normally appears as an internal computer storage interface. For many years ATA provided the most common and the least expensive interface for this application. It has largely been replaced by Serial ATA (SATA) in newer systems. http://en.wikipedia.org/wiki/Parallel_ATA
IDE cable
A liquid crystal display (LCD)
A liquid crystal display (LCD) is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly.
LCD displays are available to display arbitrary images (as in a general-purpose computer display) or fixed images which can be displayed or hidden, such as preset words, digits, 7-segment displays, etc., as in a digital clock. They use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements.
LCDs are used in a wide range of applications, including computer monitors, television, instrument panels, aircraft cockpit displays, signage, etc. They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. LCDs have replaced cathode ray tube (CRT) displays in most applications. They are available in a wider range of screen sizes than CRT and plasma displays, and since they do not use phosphors, they cannot suffer image burn-in. LCDs are, however, susceptible to image persistence.[1]
The LCD is more energy efficient and offers safer disposal than a CRT. Its low electrical power consumption enables it to be used inbattery-powered electronic equipment. It is an electronically modulated optical device made up of any number of segments filled withliquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome. Liquid crystals were first developed in 1888.[2] By 2008 worldwide sales of televisions with LCD screens exceeded annual sales of CRT units; the CRT became obsolete for most purposes.
http://en.wikipedia.org/wiki/Liquid_crystal_display
Cathode Ray Tube (CRT)
The cathode ray tube (CRT) is a vacuum tube containing an electron gun (a source of electrons or electron emitter) and afluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms (oscilloscope), pictures (television, computer monitor), radartargets and others. CRTs have also been used as memory devices, in which case the visible light emitted from the fluoresecent material (if any) is not intended to have significant meaning to a visual observer (though the visible pattern on the tube face may cryptically represent the stored data).
The CRT uses an evacuated glass envelope which is large, deep (i.e. long from front screen face to rear end), fairly heavy, and relatively fragile. As a matter of safety, the face is typically made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions, particularly if the CRT is used in a consumer product.
CRTs have largely been superseded by more modern display technologies such as LCD, plasma display, and OLED, which offer lower manufacturing and distribution costs.
http://en.wikipedia.org/wiki/Cathode_ray_tube
BIOS
In IBM PC compatible computers, the Basic Input Output System (In IBM PC compatible computers, the Basic Input Output System (BIOS), also known as the System BIOS or ROM BIOS ( /ˈbaɪ.oʊs/), is a de facto standard defining a firmware interface.[1] The name originated as the name of a component of CP/M (circa 1973-1974), where the BIOS was loaded from disc rather than stored as firmware on ROM (because ROMs were expensive and difficult to reprogram at the time).The BIOS software is built into the PC, and is the first code run by a PC when powered on ('boot firmware'). When the PC starts up, the first job for the BIOS is the power-on self-test, which initializes and identifies system devices such as the CPU, RAM, video display card,keyboard and mouse, hard disk drive, optical disc drive and other hardware. The BIOS then locates boot loader software held on aperipheral device (designated as a 'boot device'), such as a hard disk or a CD/DVD, and loads and executes that software, giving it control of the PC.[2] This process is known as booting, or booting up, which is short for bootstrapping.
BIOS software is stored on a non-volatile ROM chip on the motherboard. It is specifically designed to work with each particular model of computer, interfacing with various devices that make up the complementary chipset of the system. In modern computer systems theBIOS chip's contents can be rewritten without removing it from the motherboard, allowing BIOS software to be upgraded in place.
A BIOS has a user interface (UI), typically a menu system accessed by pressing a certain key on the keyboard when the PC starts. In the BIOS UI, a user can:
§ configure hardware
§ set the system clock
§ enable or disable system components
§ select which devices are eligible to be a potential boot device
§ set various password prompts, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized peripheral devices.
http://en.wikipedia.org/wiki/BIOS), also known as the System BIOS or ROM BIOS ( /ˈbaɪ.oʊs/), is a de facto standard defining a firmware interface.[1] The name originated as the name of a component of CP/M (circa 1973-1974), where the BIOS was loaded from disc rather than stored as firmware on ROM (because ROMs were expensive and difficult to reprogram at the time).
The BIOS software is built into the PC, and is the first code run by a PC when powered on ('boot firmware'). When the PC starts up, the first job for the BIOS is the power-on self-test, which initializes and identifies system devices such as the CPU, RAM, video display card,keyboard and mouse, hard disk drive, optical disc drive and other hardware. The BIOS then locates boot loader software held on aperipheral device (designated as a 'boot device'), such as a hard disk or a CD/DVD, and loads and executes that software, giving it control of the PC.[2] This process is known as booting, or booting up, which is short for bootstrapping.
BIOS software is stored on a non-volatile ROM chip on the motherboard. It is specifically designed to work with each particular model of computer, interfacing with various devices that make up the complementary chipset of the system. In modern computer systems theBIOS chip's contents can be rewritten without removing it from the motherboard, allowing BIOS software to be upgraded in place.
A BIOS has a user interface (UI), typically a menu system accessed by pressing a certain key on the keyboard when the PC starts. In the BIOS UI, a user can:
§ configure hardware
§ set the system clock
§ enable or disable system components
§ select which devices are eligible to be a potential boot device
§ set various password prompts, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized peripheral devices.
http://en.wikipedia.org/wiki/BIOS
Utility software
Utility software is system software designed to help analyze, configure, optimize or maintain a computer. A single piece of utility software is usually called a utility or tool.
Utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates. Due to this focus, utilities are often rather technical and targeted at people with an advanced level of computer knowledge - in contrast to application software, which allows users to do things like creating text documents, playing games, listening to music or viewing websites.
[edit]Utility software categories
§ Anti-virus utilities scan for computer viruses.
§ Backup utilities can make a copy of all information stored on a disk, and restore either the entire disk (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion).
§ Data compression utilities output a shorter stream or a smaller file when provided with a stream or file.
§ Disk checkers can scan operating hard drive.
§ Disk cleaners can find files that are unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full.
§ Disk compression utilities can transparently compress/uncompress the contents of a disk, increasing the capacity of the disk.
§ Disk defragmenters can detect computer files whose contents are broken across several locations on the hard disk, and move the fragments to one location to increase efficiency.
§ Disk partitions can divide an individual drive into multiple logical drives, each with its own file system which can be mounted by the operating system and treated as an individual drive.
§ Disk space analyzers for the visualization of disk space usage by getting the size for each folder (including sub folders) & files in folder or drive. showing the distribution of the used space.
§ Disk storage utilities
§ Archive utilities output a stream or a single file when provided with a directory or a set of files. Archive utilities, unlike archive suites, usually do not include compression or encryption capabilities. Some archive utilities may even have a separate un-archive utility for the reverse operation.
§ File managers provide a convenient method of performing routine data management tasks, such as deleting, renaming, cataloging, uncataloging, moving, copying, merging, generating and modifying data sets.
§ Cryptographic utilities encrypt and decrypt streams and files.
§ Hex editors directly modify the text or data of a file. These files could be data or an actual program.
§ Memory testers check for memory failures.
§ Network utilities analyze the computer's network connectivity, configure network settings, check data transfer or log events.
§ Registry cleaners clean and optimize the Windows registry by removing old registry keys that are no longer in use.
§ Screensavers were desired to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use. Contemporary screensavers are used primarily for entertainment or security.
§ System monitors for monitoring resources and performance in a computer system.
§ System profilers provide detailed information about the software installed and hardware attached to the computer. http://en.wikipedia.org/wiki/Utility_software